Project: Building a REST API with Spring Boot

In this guide, we'll walk through the process of setting up a simple Spring Boot project to perform CRUD operations on a Student entity. We'll cover everything from creating the project using command-line tools to explaining key annotations used in the project, testing the operations with Postman, and more.

medium blog: https://medium.com/@murariwalake/getting-started-with-spring-boot-building-rest-api-66efea30d8c5

Prerequisites:

Before diving into Spring Boot, it’s important to have a basic understanding of Java programming and RESTful architecture concepts. Additionally, ensure you have the following tools installed:

1. Java Development Kit (JDK) Java 17
2. Integrated Development Environment (IDE) such as IntelliJ IDEA or Eclipse
3. Postman or a similar API testing tool

1. Creating the Spring Boot Project:

• Navigate to start.spring.io or click on this link which has pre-selected configurations.
• Download and unzip the file into your desired directory.
• Open the project directory in your IDE (e.g., IntelliJ IDEA) by selecting pom.xml and opening it with your IDE.

2. Understanding @SpringBootApplication:

The @SpringBootApplication annotation is a meta-annotation that combines @Configuration, @EnableAutoConfiguration, and @ComponentScan. It marks the main class of a Spring Boot application, enabling auto-configuration and component scanning.

3. Adding the Student Class:

Create a Student class in the package com.murariwalake.demorestapi.model with attributes such as id, name, age, etc.

package com.murariwalake.demorestapi.model;

public class Student {
    private int id;
    private String name;
    private int age;

    // Constructor, getters, and setters
}

4. Creating the Controller Class:

Create a controller class StudentRestController.java to handle CRUD operations for the Student entity. Annotate this class with @RestController to indicate that it will handle RESTful requests.

package com.murariwalake.demorestapi.controller;

import org.springframework.web.bind.annotation.*;

@RestController()
@RequestMapping("/api/students")
public class StudentRestController {

    // Controller methods for CRUD operations
}

Annotations Used in Controller Class:

• @RestController: Indicates that the class defines a REST controller.
• @RequestMapping: Maps HTTP requests to handler methods.
• @GetMapping: Maps HTTP GET requests onto specific handler methods.
• @PostMapping: Maps HTTP POST requests onto specific handler methods.
• @PutMapping: Maps HTTP PUT requests onto specific handler methods.
• @DeleteMapping: Maps HTTP DELETE requests onto specific handler methods.
• @RequestBody: Binds the HTTP request body to a method parameter.
• @PathVariable: Variable that passed in URL. Ex: api/students/{id} in this API id is the path variable.

5. Running the Application:

You can run the Spring Boot application in IntelliJ IDEA by right-clicking on the main class (DemoRestApiApplication) and selecting “Run”.

By default, the application starts on port 8080.

Alternatively, you can run it from the command line using Maven:

mvn spring-boot:run

6. Testing with Postman:

After starting the application, open Postman and import the provided JSON file to start testing each API endpoint.

Postman JSON file

Conclusion:

In this guide, we’ve covered the basics of building simple REST APIs with Spring Boot. By leveraging annotations like @RestController and @RequestMapping, along with component scanning, we’ve created a CRUD application for managing student records. Spring Boot’s ease of use and powerful features make it an excellent choice for developing RESTful services.

Happy coding with Spring Boot!

Thanks for reading! 🙏🏻# demo-rest-api